Drive head



Dec 13, 1933.. J. J. RUSSELL 4 2,139,973

DRIVE HEAD Filed July 23, 1956 2 Sheets-Sheet 1 Dw. 13, was,

J. J. RUSSELL DRIVE HEAD Filed July 25, 1936 2 Sheets-Sheet 2 Z 26 I4- 26 I 26, l-r-n H i I I \4 r y 26' 25 2 A, 'J 02g 3 I Jaw/VJ, P011544 Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE Application July 23,

3 Claims.

This invention relates to new and useful improvements in drive heads.

One object of this invention is to provide an improved independent drive head particularly adapted for use in connection with conventional rotary drilling tables for driving cylindrical pipe, whereby the well drilling tools are operated.

An important object of the invention is to provide an improved drive head which is readily accessible and by means of which the use of the usual slips for holding the drill stem while said stem is being extended ormade up is eliminated. Another object of the invention is to provide an improved drive head arranged to engage the drill stem at a point above the rotary table, and to operate in a zone above the table, whereby the drilling operation is facilitated by elimination of the usual square drive member or kelly.

A further object of the invention is to provide an improved drive head of simple construction in which the worn elements may be quickly and economically replaced.

A particular object of the invention is to provide in an improved drive head gripping means having such construction that movement of the drill stem or other element therethrough is positively prevented and in which means for readily attaching the head to the derrick floor or other restrainingmeans is provided whereby upward 0 movement of the drill stem or other element due to well pressure may be prevented.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure l is a View, partly in elevation and partly in section, of a rotary table and drive head.

Figure 2 is a plan view of the drive head and a portion of the rotary table shown in Figure 1,

Figure 3 is an enlarged transverse, vertical, sectional view of the drive head,

Figure 4 is an enlarged vertical, sectional view taken on the line 4-4 of Figure 2, I

Figure 5 is an enlarged horizontal, sectional view taken on the line 55 of Figure 1,

Figure 6 is an isometric view of one of the slips,

Figure 7 is an enlarged horizontal, sectional view of one of the slips,

Figure 8 is a vertical, sectional view of another form of slip,

Figure 9 is a View partly in section and partly in elevation of a modified form of the invention, and

t Figure 10 is an enlarged horizontal, sectional view taken on the line lfll0 of Figure 9.

In the drawings, the numeral I0 designates a 1936, Serial No. 92,210

rotary drilling table of any conventional type mountedon the derrick floor of a well. A peripheral gear ring II is provided on the under side of said table and is in constant engagement with a drive pinion l2. on a suitable shaft I2 and is driven by a motor, or other means. A square bushing I3 is located in the customary manner within an axial opening provided in the rotary table. The usual drill stem l4 carrying the drilling tools on its lower end (not shown) extends through the opening in the rotary table and has its upper end connected by a coupling l5 to the ordinary swivel assembly (not shown) which is suspended from the upper end of the derrick.

A cylindrical housing I6, having a vertical chamber ll rectangular in cross-section extending therethroughsurrounds the upper end of the drill stem l4. The housing is supported on an elongate flat drive bar or member I 8 which is rigidly secured thereto forming a bottom for said housing. The bar is provided with a central cylindrical opening IS in axial alignment with the chamber ll of the housing, whereby the drill stem passes upwardly through the opening in bar and the chamber ll. A fiat cover 26 is provided on top of the housing and has a circular opening 26', in: alignment with the opening IS in the flat bar, to allow passage of the drill stem. The cover is secured to the housing 16 by elongate bolts 19 which extend downwardly through said housing and bar I8 and are held in place by nuts on their lower ends. From the above description it will be seen that a drill stem or other element can extend through the housing and said housing be freely 7 moved along said drill stem.

For gripping the drill stem, a pair of solid slips 20, dovetailed in cross-section, and having tetragonal serrations or pyramidal teeth 2| on their inner arcuate faces, are mounted in an upright opposed position within the chamber ll of the drive head housing, and are slidable therein.

Each slip is frictionally retained in a dovetailed vertical groove provided on the inner face of a rectangular follower block 22, which is slidably fitted within the chamber ll. It is noted that the slips, followers and the chamber within the housing are all of substantially the same depth whereby when the gripping members are in engagement with the drill stem extending through the housing, movement of said gripping members in either vertical direction is prevented by the cover 26 and the bar l8.

An adjusting screw 25 for moving the slips into engagement with the drill stem is threaded through the wall of the housing H5 at each end of the chamber H and has its inner end engaging a recess formed in the outer face of the follower block 22. As said screws are rotated to move inwardly, the followers and slips are The pinion is mounted pressed by a screw jack action into gripping engagement with the drill stem extending through the housing (Figure 5), and due to the pyramidal shape of the gripping teeth 2| of the slips movement of the tubing in any direction is prevented.

Vertical drive posts 21 are suitably secured to the upper surface of the rotary table and extend upwardly therefrom to engage the extended inner faces of said slips prevent movement of the drill stem. in any direction. Rotation of the table rotates the stem to perform the drilling operation. As the drilling progresses, the stem moves downwardly, which causes the drive bar to move downwardly between the posts 21, until said bar rests on the upper surface of the rotary table. At this time the coupling [5 is disconnected from the upper end of the drill stem and another section of stem is secured thereto, whereby an upward extension of said drill stem is formed, and the upper end of the new section is connected to the swivel assembly by means of the coupling l5. After such connection is made and while the drill stem is held suspended from the swivel assembly, the adjusting screws 25 are loosened and the slips retracted, and the drive head moved upwardly to a position on the new section of drill stem below the upper ends of the drive bars 27, whereupon the adjusting screws are again tightened and the cycle of operation repeated. Thus, it will be seen that the head not only drives the stem, but also serves to hold said stem while additional lengths are being connected thereto. It is understood that the head may be lifted in any suitable manner. If desired loops or eyebolts 28 placed on the upper side of the bar l8 near its outer ends may be utilized. It will also be seen that said loops or eyebolts may be used for attaching cables or other means for tying the head to the derrick floor, or other holding means, to prevent upward movement of the drill stem should the pressure within the well become great enough to cause said upward movement.

In case the slips become worn or for other reasons necessitating replacement, it is only necessary to loosen the adjusting screw 25, remove the cover 2%, renew said slips and replace the cover, and the head is again ready for use. It will be seen, therefore, that the head is readily accessible and does away with the lengthy operations necessary with the usual square drive member or kelly.

A modified form of the invention is shown in Figure 9 and Figure 10 wherein the drive head is identical with the exception of the drive bar l8a, which is reduced and has its arms shortened, as shown.

An elongate cylindrical sleeve 29 surrounds the drill stem and drive head and is provided with an annular flange 30 near its lower end 3| which end is reduced and square in cross-section to fit tightly within the square bushing l3 provided in the rotary table. The shoulder 32 formed between the annular flange 30 and the reduced lower portion 3| of the sleeve rests upon the rotary table to maintain said sleeve in a vertical upright position. .Diametrically opposite vertical slots 33 are provided in said sleeve and the shortened 'arms of the drive bar l8a are slidably mounted therein. A flanged cover or cap 34 is suitably secured, as by set screws 35, to the upper end of the sleeve, as shown in Figure 9, and is provided with a central axial opening 34 through which the drill stem M extends.

In operation, rotation of the table I!) acting through the square bushing in said table rotates the sleeve 29, whereby the arms of the drive bar I 8a are engaged to rotate the drive head as hereinbefore described. The substitution of the slotted sleeve 29 for the drive posts 21 and the reduced drive bar I 8a are the only structural changes in the form previously described.

Another form of slip is shown in Figure 8 in which gripping teeth 2! are mounted on sectional blocks 40 and tightly fitted in a follower block 22 to form a complete slip as shown. This form of slip is advantageous in that sections of the gripping teeth which become worn may be replaced without necessitating replacement of the entire slip.

What I claim and desire to secure by Letters Patent, is:

1. A drive head including, a housing having an element to be rotated extending therethrough and adapted to be movable vertically with relation to a rotary table, said housing having retractable slips therein for engaging the element extending therethrough, the housing being mounted centrally of .a laterally extending drive member, upwardly extending posts carried by the rotary table and engaging each end of the member on opposite sides thereof without positive connection therebetween whereby the housing is movable vertically as it is rotated.

2. A drive head including, a housing having an element to be rotated extending therethrough and adapted to be movable vertically with relation to a rotary table, said housing having retractable slips therein for engaging the element extending therethrough, the housing being mounted centrally of a laterally extending drive member, and an elongate vertical sleeve adapted to surround the housing and connected to the rotary table so as to be rotated thereby, said sleeve having vertically extending slots formed therein adapted to receive the end portions of the drive member whereby the housing is movable vertically as it is rotated.

3. A drive head including an elongated lateral drive bar, a housing mounted in the center of said bar for receiving an element to be rotated extending therethrough and adapted to be moved vertically with relation to a rotary table, vertically elongated retractable gripping means in said housing having relatively fine teeth for' gripping said element, a removable cover on said housing for preventing upward displacement of the gripping means therein, an elongated vertical sleeve adapted to surround the housing for connection to the rotary table so as to be rotated thereby, and means for connecting the housing and sleeve whereby said housing is movable vertically as it is rotated.

JOHN J. RUSSELL. 

